The present invention relates to a liquid crystal display (LCD) and an LCD panel which each include a component to absorb light having a particular wavelength.
A liquid crystal display is advantageous in that the display can be thinner and lighter than a Cathode Ray Tube (CRT generally called a Braun Tube in many cases). Therefore, usage thereof becomes wider with development and advance of a viewing angle widening technology and a mobile picture technology.
With widening uses of a monitor for a desktop personal computer or for a printing and designing jobs and for a liquid crystal television set, demands for color purity of blue, green, and red as well as for color reproduction of gray scale such as a color of skin of a human have become stronger. This leads to application of color filters to increase color purity of three primary colors as a basis of the color reproduction. As for a technique to use color filters, for example, JP-A-2002-40233 describes a technique to use a selective wavelength absorbing filter to suppress unnecessary emission of light from a backlight.
On the other hand, since a liquid crystal television set requires high luminance, the backlight having high luminance is generally employed. However, when the luminance of the backlight becomes higher in a liquid crystal display, there arises a problem in real black color representation. That is, since the LCD panel serves as an optical shutter to adjust light of the backlight, it is almost impossible for the following reason to completely interrupt light at black representation. The display panel has transmittivity of a finite value. A product between the transmittivity and the luminance of the backlight leads to luminance of a finite value at black representation. Therefore, when a backlight having high luminance is used, it is also possible to increase luminance at black representation. This arises a problem that black cannot be clearly displayed on screen images of content of a movie or the like which have relatively low luminance, for example, screen images of scenes at night.
For example, JP-A-2003-84271 describes a technique for use with a liquid crystal display requiring high luminance to display white and low luminance and a high contrast ratio to display black. According to the technique, luminance is suppressed at black representation without reducing luminance at white representation.